I'm trying to DIY as much as I can on this tank, so far I've made a canister filter, a yeast based CO2 system and an acrylic top. Next I'm probobly going to make a solenoid and this CO2 regulatorGood luck!
The only "cheap" way is to get stuff second-hand or by doing stuff yourself (DIY). Both are possible and DIY can be very enjoyable and rewarding...as well as educational. Check out the DIY forum on this website for all kinds of great ideas on making your own lighting, filters, CO2 system, stands/hoods, etc...
Welcome to APC!