You said 4-5" but I assume you meant 4-5' (feet). That's a really huge pine, and if you have a good many of them, there is value I the timber. I've gotten as much as $200 for a 7x16 trailer load of nice pine trunks before, and none of them were over 24". That's me hauling them to a local sawmill, but 4-5ft is absolutely huge, and the right person will pay you well for them. I'd start by putting an ad on Craigslist with pictures since it's free and has a broad audience.
