from my limited expierience you can do 10 gallon setup from walmart, 10 gallon tank, 30 gallon filter, im guessing since your limited on money our not gonna do a reef, so you can use thier lighting as well as heaters powerhead etc, get salt and declorinator from a petstore set it all up and your good to go prolly under $75 UNLESS your doing a reef
my first ever salt was a 10 gallon, since i live almost on teh beach i used beach sand beach water beach rocks a 10 gallon tank 30 gallon filter little powerhead frmo walmart lighting from walmart etc and a couple damsels from teh lfs it ran fine till we moved a year later, now the setup is a 20 gallon tall same basic principal, we live in flroida might as well use it to your advantage, as for my 180 ive got lots of money in it ive done it all the right way but its a pain in the as$ hope this helps maybe a little, thats how id do it if i were wanting one with little money others will proly differ tho