You mentioned the cost of the filters, heaters, etc. Buy them on line. You will save in the neighborhood of 40 to 60 percent compared to the LFS or LPS. To give you an example, when I bought my Fluval 304s, they were $149 at Petsmart and I paid $89 plus shipping from Petsolutions.com. The difference is enough to pay for the heater and some plants.
Also, if you get an air pump, don't go for the cheapest one you find. I originally bought the el-cheapo and it was so noisy (even though it said "silent" on the box) that I took it back. The others of the same brand were the same (I took them out of the box at Petsmart and plugged them in). The employee suggested a Rena brand which was the most expensive they had but it was dead silent. I now own 4 of them.
Also, if you get an air pump, don't go for the cheapest one you find. I originally bought the el-cheapo and it was so noisy (even though it said "silent" on the box) that I took it back. The others of the same brand were the same (I took them out of the box at Petsmart and plugged them in). The employee suggested a Rena brand which was the most expensive they had but it was dead silent. I now own 4 of them.