Group Rate @ B&b

So long story but I’m getting married in a small town in about 7 weeks with limited accommodations and booked a nice B&B in town about 9 months ago. I just wanted to get it off my list but I realize now that was a mistake. I signed a contract and paid a $700 deposit for 10 rooms for my wedding party at a group rate of $175/night per room to “lock in the booking.” I added 5 more rooms about a month ago without updating the contract (done over email) at the same rate. I am getting married in the low season and realized that I could book a room at the B&B for $125 after taxes and fees from a third party site or $145 after taxes and fees directly from their website. Apparently the group rate I got was an average rate that included their high season rates. This seems ridiculous to me to pay a premium for an advance booking especially since we are booking nearly every room they have. I contacted the lodging coordinator for clarification on this and asked her if we could renegotiate the group rate something closer to the current going rate and she seems open to it although she said this would change it from a flat rate to a variable rate by the type of room (premium, deluxe, or standard) which could end up costing some guests more. I should say members of our wedding party are paying for themselves and are already aware of the $175/night rate and agreed to it so it’s not a huge deal, however I feel guilty that all of us are being overcharged. All told, we are overpaying by about $900-1,500 depending on what rate you go by (third party or their website). Any recommendations on what if anything else I can do? I guess I can just wait to see what she comes back with and see how it compares with the original rate. Also curious if anyone has ever heard of something like this before - I understand Bed & Breakfasts operate differently than hotels so maybe this is standard for them?