You're definitely in a tough spot. Heed
@headednorth 's advice and just start saving. I've only been at it for 2 years and I'm not that much better off than you. I sprung for the TSUSA membership recently and it's perfect for someone like me who doesn't routinely have hundreds of dollars for cases of ammo. Especially now when things are in and out of stock in a matter of minutes, I can buy 1000 rds. of .22 here and 400 rds of 9mm there, and, well, I've basically stopped with the 5.56 until it drops back below .40/rd. By then I should have enough money for case, maybe. It's not a super efficient method, but it works for me.
The free shipping is abosultely paying for my membership as I've only been a member since July 2nd and already saved $62.
Also, in a thread related matter, shipping and processing is super quick! I assume because they have so few sku's in stock, but, ordered 2 bricks of CCI SV Monday, shipped yesterday, arriving today.