I would never spend more than $100 on any of the Hortons manufactured by the old company that is no longer in business. That old Horton 150 I would not spend more than $50 as they were inexpensive bows even when they were new. If there is a problem, you basically have a useless piece of equipment. Horton Crossbows was resurrected under the TenPoint family tree and those bows are warrantied by TenPoint.
As far as what new bow to recommend. I am partial to the Wicked Ridge line, manufactured by TenPoint, at that price point. Still an American company with great customer service. Yes, you can find cheaper bows out there, but most will be manufactured in Poe Lang Taiwan or China.
My Horton 175 was appraised for a trade in at $175. The 150 was a "lower" model. Personally i wouldn't give more than $150 in very good to excellent condition.. The Horton was a good crossbow. Had a 150 for 8 years, and a 175 ever since, and it still shoots great
My buddy had a Horton Bow with a lifetime warranty when we heard a noise while we just got done hunting and discovered a limb cracked. He dropped off the bow at a authorized dealer where he bought the bow and they had it for months. They kept giving him the run around saying they received the wrong limbs etc. This was about six months before the company went under and he never did get the bow fixed. The new company did not honor the lifetime warranty.