Anyway, there's a lot more work in desoldering two entire keyboards (or just one), and swapping springs, than just buying the MX reds in the first place. Plus the cost of the springs. Unless you particularly enjoy that kind of repetitive work, or need the desoldering practice, finding MX reds might still work out easier 
You're right, but as a student I have a bit more time then money... Also, the switches are PCB mounted, so I guess this makes it a bit easier.
Quick calculation:
Cost of the keyboards (incl. shipping): 9€
Switches: 210
Cost per switch: 9/210=0.04€
Cost of 200 Sprit springs (plus shipping $8): 24.70€
Cost per spring: 24.70/200=0.12€
Cost of modded Red switches: 0.04+0.12=0.16€
Total cost for 200 modded Red switches: 0.16*200=32€
Cost of 200 wasdkeyboards.com Red switches (plus shipping $24.15): 127.40€
Cost of 200 maxkeyboards.com Red switches (plus shipping $7): 130€
Cost of 200 7bit Red switches (plus shipping 4€): 134€
Looking at the calculation, I think the price difference is worth my time desoldering the switches.
While writing this, this idea came to me, that I could buy another used Cherry with Brown switches and use its springs. I'm not sure how the Brown and the Red springs compare to each other.
EDIT: Sorry, the forum messed up the Euro-signs.