I know it's a bit of an ask because in terms of taste it's nowhere near an exact replacement for meat or cheese, but tofu is both cheap(ish) and healthy. Unless you have a soy allergy, do incorporate that rather than Impossible et al.s bleeding, complicated protein remixes powered by VC money. (I don't have a hardline stance against vegan meat replacements but when they are too pricey for you there's no reason to buy animal meat.)