A Winchester Model 1894 in .30 WCF is not a rare firearm, in any year of production. It is a classic, and a desireable firearm, and being pre-1964 it will be an heirloom, meaning your great-grandson should still be using it after you're gone, but it's not likely a museum piece. 1928 is well removed from the Old West and there is no special cachet attached.
What is the length of the barrel, is it round or hexagonal or half-and-half, and what's the length of the magazine tube under it? Is there an intact saddle ring? Crescent or flat butt plate? Period optional aperture sight? Any factory engraving, or skilled embellishments by a master gunsmith? Is it a ‘1 of 1000’ superior quality factory special? Has the wood and/or metal been re-finished? These are some of the basic questions to ask once you've established the model, year, and chambering of your lever gun.
Then again, it could be an utterly ‘unique’ specimen, meaning ol' Bubba has had a go at 'er. Authentic, tasteful Indian tack decoration might increase interest, but Bub's carving of the deer he hopes to bag will not. Drill and tap for scope mount, chop the length on either end, Parkerize it like a Garand, there's no end to the abominations possible.
On-line pictures will rarely be useful for determining bore condition. A lot of these have very little discernible rifling (not to mention pitting). And noticeable crown wear, because it's easier to clatter a cleaning rod around up front, than to remove the bolt and come in from the rear (or to just do things carefully).
If you want the gun, and can buy the one pictured for $550, I think you should definitely do it, pending function and bore check out. Up to $750 would require far deeper inspection than a post on this forum. Cheaper and you should have already jumped on it. The variance of your local market will also apply.