Myself and friends have purchased from aliexpress seller Ridespice with great luck. Bassalt brake surface, chose your hub, spoke, nipple colors... I also have a set of SuperTeam wheels that are a bit lighter. Have had great luck with all of them. Look for extended reviews. Should be able to get a nice set of 50's for $300

I'm hard on wheels.... really hard. I've had many wheels fail with less than 2000 miles and the China carbons have held up very well for me. No issues with over 4000 on my two sets and almost 10000 on one of my friends. We're all over 200 pounds, rough roads and pretty aggressive riding.