He spent $2.00 on seeds and $8.00 on soil for a total of 2+8 = $<<2+8=10.00>>10.00
He sells each of the 20 basil plants for $5.00 so he makes 20*5 = $<<20*5=100.00>>100.00
He made $100.00 from selling basil plants and he spent $10.00 to buy and grow the seeds. His net profit is 100-10 = $<<100-10=90.00>>90.00
#### 90