What are the price/features tradeoffs to consider when buying a new brew kettle?

I'm in the minority here, but I just can't, for the life of me, figure out why anyone would ever bother spending so much money on a brew kettle. What do you get for the extra money? Let's break it down.

1) A built in thermometer - Here's a tip for you, water/wort boils at 212F ;) Seriously though, if you NEED a thermometer because you're monitoring the temps during chilling (or whatever) a decent probe thermometer will cost you $20. Plus, you can move the probe around to ensure you aren't in a single hot/cold spot.

2) Ball Value - This is actually pretty nice, but is it "$300 nice"? Furthermore, you can purchase a weldless valve kit and make your own valve in an aluminum pot. Or pay someone a couple bucks to do it. Or, you can live with a $15 Auto-Syphon.

3) Stainless Steel construction - Very nice, super shiny, fairly expensive. The myth about aluminum and Alzheimers has been disproven, so I'm not sure what the extra benefit would be.

4) A sight glass - For volume estimation. You can replicate this by marking some lines on your mash paddle for your pot for the different gallon levels. Or, you can open up that dusty old geometry book and figure out the volume of a cylinder (Pi * radius squared * height).

As stated in the comments, this is going to be your opinion ultimately, but you should break down the features you'll get from the nice kettle, and decide if its worth it compared to the baseline price of about $30 for a 10 gallon aluminum "Tamale Steamer". Its what I use, and is available in most Latin grocery stores. A 10-fold price increase for me to go from my beloved steamer to a "real" kettle like the one you linked to is FAR to excessive for me to be considering it at the moment.

I own the above referenced kettle and have been very happy with it, however prior to buying it I brewed in a 10 gal aluminum stock pot that set me back about $50 and worked great for years...I still use it to heat spare water. If you think $300 is too much to spend, then it probably is, particularly since there are so many other less expensive options available.

One of the things I have always liked about the home brewing hobby is that you can get started and make excellent beer without investing a lot of money in equipment, but there are many options for equipment that can be added over time. Some of those options may improve your beer, but others often just make things more convenient.

IMHO, the primary consideration for investing in a substantial kettle should be volume: A 10-gallon kettle limits you to 5 gallon batches, but a 15-gallon kettle will let you make 10 gallons. A kettle like you have referenced should last forever -- I purchased a similar one in 1995 and it still looks brand new after 100's of batches. So consider whether you might want to increase your batch size down the road.

I brewed "on the cheap" for many years. I started with one of those "speckle enamel" canning pots, used Rubbermaid coolers for mash tuns and hot-liquor tanks, did my vorlaufing by draining wort into a small pot that I poured by into the mash by hand, etc. Over time I upgraded my kettles, added pumps, and I now brew with a Sabco RIMS system that I picked up second-hand. Did those additions improve my beer? Some did: A thin-walled kettle is much more prone to scorching than one with a thicker bottom that gives more even heat distribution. But many of them just made things easier, shortening my brew day.

So, is that kettle worth the money? You can certainly get by with cheaper options. But I do really like the dial thermometer because I can see at a glance, from a distance, whether I am close to a boil and need to watch for a boil-over. The false bottom make wort transfer much easier because most of the hops stay in the kettle. The ball valve makes it easier to move to pumps and counter-flow chillers, etc. A welded fitting has fewer seams for cleaning. I think that this is a fair price for a kettle of this quality and features. So it really comes down to your budget, and how important those features are to you. I have found that small improvements in process that may be expensive could never be justified if you are looking at them as a businessman would with a cost/benefit analysis -- but they accumulate and make the hobby more enjoyable for me.

Money is always subjective, and so is what equipment a brewer needs to complete the brewday. It depends upon your process.

If you're not all grain brewing, then you can make do with a lot less. If you can do a full wort boil and have some way to get the wort out (e.g. a gooseneck siphon if chilling outside the kettle, or a regular siphon for an IM chiller) then that's all you need at a minimum. A thermometer isn't really needed for monitoring wort since it's just being boiled (it can help with curiosity and impatience - a watched pot never boils!), and sight gauge is not necessary since volume is not so important - the gravity is chiefly determined by the amount of extract you put in and the volume can be adjusted with top-up water in the fermentor if needed.

If you're all grain brewing, then getting by without this can still be done, but the process has many more variables, and more things can go awry if not monitored. You can brew AG without knowing pre- and post-boil volume, but when things don't go as you planned you'll have a harder job figuring out why the beer didn't come out as intended. The volume measurements from a sight gauge help you dial-in and fine tune your process.