Behringer U-PHORIA UM2 Audiophile 2x2 USB Audio Interface with XENYX Mic Preamplifier | for Recording Microphones and Instruments

You can get the cheapest Behringer interface on Amazon for $50. If you can't budget that, then you're in the wrong game, I would say. Start digging under the couch cushions and collect some bottles, sell some plasma, busk for the afternoon, and make yourself your some music. Nothing is impossible.