Sam, overall I like the quality of the photos. The contrast of the colors is very nice.
1. The single greatest thing you can do to improve your website is to increase the amount of photos in each set. 24 is way to low, particularly when Im purchasing with credits. The average number should be around 40 to 50 pics in each set.
2. The photos overall look good to great by todays standards, but do try to upgrade to the most advanced camera if you can. You might check out the photos at bryci.com Their photos seem to always be on the cutting edge of hi def.
3. If you can find time and resources, some time down the road you might consider re mastering the earlier picture sets.
4. Consider removing the glossy and ultra polished look from the videos and just try to have the best hi def camera that you can. The glossy look works well for the photos, but it makes the videos seem inaccessable. This is one of the reasons Im always trying to persuade you to shoot for other sites.