You know, if it's a difference between riding or not riding for a month get the WM bike at $89 or whatever and just goodwill it when you leave for BT.
The seat will hurt like hell, the shifting will be *****e, it may even make your knees hurt after a 25 minute ride. But it will certainly give you the painful perspective that will guide you to purchase a higher quality bike when you get done with BT.

Just find a way to ride for the next 30 days, that's the important thing