|It depends on which model you develop within.
A) If this is a project developed on request:
1) Hourly rates (development, test phase) X developers + server cost + adm. time
2) Fixed cost. Stipulated estimate of 1). Add some slack for unseen costs/time.
In addition segment the total cost by development, operation and maintenance.
Hourly rate is based on market price + adjustments for how good you are/experience and your market value in general (a well known company will be more expensive than a new established one).
B) If this a volume project for the market:
1) Your net cost (time, marketing, rent etc.) / estimated sold units + provision.
2) Competitive: What do your competitors price their similar product at?
In addition you could choose sub-models such as subscription, upgrades etc.
As always, there are different risks involved, especially with model B.
Hope this will give you a starting point.