Just substitute a 0 instead of the script to check stock, it'll probably be right 99% of the time.
Have had tons of different VPS/Dedis throughout the years but never a BuyVM because everyone time I'd want to buy one it'd be out of stock and I'm not going to wait forever for a moderately priced VPS.
My problem with BuyVM is that VPS's are to an extent, impulse purchases, and if you never have stock then that doesn't work for me.. I'm sure not the only person on here who buys VPSs like this, but I guess BuyVM must be doing okay if they don't want our money.