Re: Cuddy cushions
I own an upholstery shop in FL and here is what I can provide you, information wise:
If your boat is a Bayliner Throphy W/A cuddy (model 2002), then your cushions aren't mounted on a plywood base. They are upholstered covers. There should be 3 of them; 2 on the sides which meet in the middle and a filler cushion for when you put the table top down on the berth rests.
These are a bit tougher to upholster than a standard cushion as the covers/foam are tapered outward on the sides to fit the outward flare of the hull. Zippers should be placed on these tapered edges. A quality commercial machine with a walking foot (and a welting foot if welt *cording* is desired), but a home machine may work if the material is not too thick. The biggest problem DIY'ers face when sewing these cushions to not knowing how to line up the corners as the top of the cushion is a different size than the bottom.
From a labor cost standpoint, assuming your cushion is approx 6.5' long x 2' wide, the average price would be approx $100-$135 per side and an additional $50 for the center filler piece. Material & labor should still bring you in under $500. You can do it cheaper, but the price I'm quoting you is for a professional job. If the material is purchased right, you can knock another hundred dollars off of that price. By DIY, you will save money, but it may also look like a DIY project. It's up to you to determine what you want and what you can live with.
If you need any additional information of have any questions, please feel free to PM me and I'll help out any way I can.