I bought the RV-Co Port-A-Step last Spring, it was less than the Deck, I think in the $500 range. We already had some steel steps from another company, but they were too hard to put up for one night stops. My dog could not safely do the stock trailer steps even for an overnight.

The metal non-slip surface of these was also a no-go for the dog. I got some "Prest-O-Fit 2-0421 Ruggids RV Step Rug Sierra Brown 23 In. Wide" covers for the steps and put a small rug on top. These help clean your feet off as well.

They fold up and fit into my basement side storage right by the step.

The owner is easy to get by phone and easy to work with. I did have one issue where it seemed the rail was too long to fit properly into the receivers. It may be because I have not fully extended the steps properly or they need some lubricant. I got around it by flipping the rail upside down which positions the posts slightly closer together. Also, during long term use, the top step will try to creep in towards the camper slightly. There are hooks to bungee it, but I think I will use some rigid hardware. Since it is so portable, when I am at unknown overnight stops, I put a lock cable around it and the original steps. It does not fasten to your old steps, it just sits on top. It is important to have the two measurements when ordering: camper floor height and top step height. In my case, to make it come out right, they added a 3" lift to the top shelf.
Before steps, I did the ramp thing. Fifth Wheels are usually so high that the angle is unusable for an impaired dog. I had two of the ramps that met on a halfway down platform. It was a real dog and pony show setting it up and the top ramp had to be removed for the humans to get in. I would not recommend that approach.
We have had some knee issues and really appreciate these steps, especially when carrying a load.