If you want to save money and not spend it on vitamins, grow seeds that look like the common seeds in the supplies section. They will be more likely to grow in level 1 soil. The more gnarled and bumpy the seed, the more challenging growing them will become. You should be able to save enough money by growing the common seeds. Patience is a great virtue in this game.
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Vista™ Home Premium (6.0, Build 6000); AMD Athlon 64 X2 Dual Core Processor 4800+, ~2.5GHz; 1918MB RAM; DirectX 10; NVIDIA GeForce 6150SE nForce 430 128MB RAM; 1024 x 768 (32 bit) (75Hz)