Front wheels are generally lighter and take a lot less abuse than the rear wheel. If you don't mind miss matached rims (or will take all the stickers off), I'd just get a new wheel with 15mm thruaxle, or splurge for a new wheelset. trying to lace up a new hub to your old rim with old spokes could be a hassle because of different spoke lengths required and because they are used spokes. The wheels off nashbar below would come in right at $300 today with their discount, includes all the endcaps for 135QR rear and 15mm thru front, tubeless ready, and weighs less than 1800 grams. Pretty good for $300.

Mavic Crossroc XL WTS Mountain Bike Wheels | Mavic

Reynolds R27.5 AM Mountain Wheelset

 

Any thoughts on these wheels? I could get a single wheel for $100 or a set for $230. They seem to be light weight, and from a little googling they also seem to hold up well.

DT Swiss X392-370 Tubeless 27.5" Front Wheel 15mm

 

A good wheel for the price. If you're good with the width, that'll last you for years. It really comes down to how wide a wheel rim you want. Current trend is to go with a wider rim to maximize tire volume and avoid rolling the tire, but at a weight hit. A 20mm internal rim width isn't bad. It's what I'm using on my bike right now, but I'm also in the process of building up a wheelset with 29mm internal width. After riding a fat bike, I can really tell how much more grip I can get in corners with a bigger tire.

 

Will the rim width affect what size tired I can run? Right now I'm running a Maxxis Ardent 2.25 in the rear and a 2.5 minion up front. I'm probably going to exchange the minion for another ardent or a nobby nic, but the trails I ride most frequently require a nice, thick, knobby tire. I just don't want to have to change up tires for the wider rim.

 

I don't know the rim width of your current wheel set, but with a 2.5" tire, I wouldn't use less than a 25mm internal rim width if I had a choice. I would, but deep down, I'd know that a wider rim would make the tire work better.