You need to rethink owning a pet if you can't afford less than $5.00 per week to feed one. No pet is free but there's not a lot of pets out there that are as low cost to feed as a snake!Originally Posted by SirMontyPython
As far as feeding a medium sized rat to a barely 500 gram snake, well no wonder it regurged! That's a huge meal and likely your snake could not digest it faster than it started to decompose inside the snake and triggered the regurge. It has nothing to do with "stretched his neck way big", it has to do with being an inappropriate prey size for that snake. We have a number of snakes in that size range. None of them get anything bigger than a almost weaned pup rat or young weanling once per week and that's sufficient for their needs without overstressing their digestive process.
Causing your snake to regurge due to inappropriate feeding is harsh on your snake. When they bring up that prey they also bring up some of the most potent digestive acids in the animal world. That acid burns their insides when it comes up, it can even burn their outsides if they lay on it in their tub. Snakes have died from regurging. I hope you gave it time to heal properly before offering food again and did some research on post-regurge care.