Comps are important, no question there. Just as important is the market itself and what direction it's heading.
Last year I represented a Seller on a 3 bedroom, 2 bath property in SSF and the property sold for $585,000, If we priced it today I imagine I would have to recommend that it be priced at $629,500 which tells me that the market from last year to this year has gone up 8.25%.
Lastly, counsel your Buyers to write 2 or 3 different offers. With good communication between you, your buyers and the listing agent will help you determine which would be the best offer to present when that time comes.
Good Luck & Congrats to your Buyers!