For perspective, Yolodice allows you to withdraw for only 15,000 Sat (regardless of the network), they probably make a loss on that but for people like me it keeps us happy.
Sorry for mentioning another site here, but if you're interested in an at-cost model check out the fees on bustadice.com . It constantly changes based on network conditions, but is designed to exactly model the site costs. For reference at the moment:
Deposit fee: 368 satoshis (since there's a consolidation overhead for deposits)
Instant Withdrawal Fee: 45580 satoshis (should confirm in < 2 confs, with a 95% probability)
or
Delayed Withdrawal Fee: 9010 satoshis (delayed until someone else makes a withdrawal)
Although a big part of the reason it's so cheap is due to optimization (like using segwit), but I think it makes a good base-line as it's not subsidized (or a profit center). Not that it's particularly relevant, but the amortized investor commission is 25%