new price on backorder?

What is the name of your state? oregon

I ordered a french horn from a company in Massachusetts last October and I verbally asked if the price would be allowed to change before delivery. They said no, no price changes, but...I found out later a friend of mine ordered one at the same time and he received an order form in the mail(I ordered mine on the phone) that said that the price could change--I did not receive this form. So, I have an invoice that says how much I have paid, how much is still owed (the original price) and we are in dispute over the price they want to raise it to. The horn is due to be finished in June and I think they should have to sell it to me at the original price. What do you think? thanks.

[JETX]

"I have an invoice that says how much I have paid, how much is still owed (the original price) and we are in dispute over the price they want to raise it to."
*** Your post says that you have an invoice showing the original purchase price. Lacking any other agreement, the invoice is likely your contract. And as such, the price shown cannot be altered or changed (by either party) without the acceptance by the other.

However, even though you have a contract law issue, any challenge will be affected by the reality of the seller being in a different state and your need to take any legal action in his 'home' state.

I suggest sending him a letter (certified RRR) including a copy of your invoice and demand that he comply with the agreed price and to confirm that in writing. If he refuses, you will have to make a decision on whether to demand a refund due to his breach... and the possibility of legal action, or to accept his 'unilateral' adjustment of the purchase price.