I just looked at the prices there - 43 charts for the Ches. Bay = 296 bucks.
I prefer my chart book from WM for 39 bucks. Same size, same charts.
I do not disagree that Chart Kits are an economical alternative to Print on Demand Charts. Unfortunately, however, they are frequently already out of date whereas POD Charts as distributed by the NGA are usually current within two weeks.
For example, overhearing me complain about the fact that our Region 8 Chart Kit, 11th Edition, was badly out of date and I needed to sit down and make corrections, my (much) better half stopped by WM and bought the "current", 14th Edition, of the same Chart Kit for me as a gift. As one cannot look a gift horse (or Chart Kit) in the mouth I thanked her and dutifully retired our old 11th Edition after patiently transferring many of my notes as to anchorages, Bridges, etc. to the new chart kit over several evenings. With only a few exceptions, the "new" chart kit was little different than the old and did not include many of the up-dates from the Notice to Mariners I had patiently added to the "old" chart kit as the various NTM's were released. (Had I realized this before I began annotating the later Chart Kit I would simply have returned it. Unfortunately, I did not and did not feel that once marked, I could do so.) N'any case, I have since purchased another Chart up-Date Kit (rub-on symbols etc) and am now up-dating the "new" Chart Kit although that is a tedious process and hard on the eyes.
The differences in the up-dated POD Charts and Chart Kits (for example) are not immaterial. If one were attempting to enter the Manatee River at the south end of Tampa Bay, for example, with the "current" Chart Kit one would find oneself desperately looking for range marks (or lights at night) at a crucial junction in very "thin" water. They no longer exist, having been replaced a year or so ago by a couple of marks on pilings that denote the outer reaches of dangerous shoals but not the safe path through them previously provided by the Ranges. (The CG's rather lame, IMHO, excuse for this was that power yachts making way under GPS to often ran down the range marks that were costly to replace!?!) Since we already know the safest tracks through the area, and bearings to maintain to the marks that do remain, it is not much of an issue for us. For a new comer that has not previously transited the area, however, the out-dated charts would be a problem, particularly at night, as the new and remaining marks have been renumbered, which would confound confusion if come upon in the dark. The POD charts reflect current actual conditions but, of course, do not make for relatively easy transits as did the ranges.
Given the foregoing, if I had to have charts so quickly that I could not confirm and make up-dates, I would certainly go with POD. Having more time, the Chart Kits and books, together with an up-date kit and recent NTM for the regions, are an economical alternative.
PS: One can get a sense of the age of a chart by inspecting the Compass Roses that show the local magnetic variation, which will be dated as of the time the chart is issued and list the annual rate of change.