David,
According to the 6th edition of the Blue Book of Modern Black Powder Arms, the Uberti Santa Fe Hawken in 100% condition is $395, 98% is $335, 90% is 245 and 80% is $205. It says the last MSRP was $420.
This book is a few years old now and prices have undoubtedly changed a bit since it was current. I would certainly consider this a real low ball valuation on that rifle, especially. I checked the Pedersoli Hawken and it also runs about the same prices, and I am sure the last time I saw a Pedersoli Hawken with a maple stock, it was in the $1,000 range, MSRP. So, that's what I got.
Sorry i am not involved in the trade anymore or I might have a bettler idea.
Is that a .53 cal or a true .54?
John