The great wave design sounds like tsunami RMCs by Hokusai as a guess and these were released in 2005/6 depending on the selvedge and waistpatch. All of those that were made have long sold out and its a popular collectors design.
The RMC x Gardener design should have 2 waistpatches on the back, again quite a rare piece although not particularly popular due to the lack of embroidery ( the images were printed on and comprise Ninja Monkey with scroll and Samurai Crest ) but still again another nice collectors piece given not many would have been produced and it was an Asia only release.
As for values, well always very hard to say, condition is going to be a major factor and of course the size ( popular sizes will attract more buyers than say very large sizes ). Also desirebility and rareness come into it and as always the market will dictate how much buyers are willing to pay.
This is the Gardener collab jeans;
This is the Tsunami Wave Jeans;
Anyway welcome to the forum and hope that helps