I'd suggest making 5-10 of each the following accounts before starting:
- 60 Strength, one attack, one prayer, one defence.
- 60 Defence, one attack, one strength, one prayer.
- 70 Range, one attack, one strength, one prayer, one defence.
- 70 Mage, one attack, one strength, one prayer, one defence.
- Finally a hybrid, 40 attack, 60 mage, 60 range, 70 strength, one prayer, one defence.
Once the accounts start selling, you can then start making the pures on request, while having a constant stock of accounts incase people want an F2P pure.