Definitely - the merchant doesn't have to pay shipping if they're next to the factory, and discounted "used" floor models which are sold slightly damaged would be a cool feature.
OK, then there's more incentive to pay attention to the world. This is a Good Thing. Not sure how the showroom model of a mech might be significantly damaged--possibly the joints stiffen up because it's been sitting there, but that ought to be curable at any mechanic. Now, buying the dealership's loaner...that might be touchy. Used-mech discounts more generally is badly needed, IMO. Otherwise, the salvage devaluation is just a slap to the player.
As per the random gouging, this could all slide back to having a broadly player controlled economy - you might not ever get a Savin as cheap in Cayley, but you could get it cheaper if you poured enough wealth into the area to enable the shops to buy more stuff.
The gouging wasn't actually random, so much as I was worrying about player perception. If I'm not actively taking shuttles around, I have no idea where the Spinners and Rocks are in relation to each other. Thus, telling me that I have to pay more for the Savin I'm ordering because of shipping might seem like gouging.
Something to keep in mind--it should probably be cheaper (in most circumstances) for the player to just order something in an "expensive" area than to take the shuttle to a "cheap" area, order the something there, get it, and shuttle back. Otherwise, there's much less point to the mechanic, let alone making a mockery of shipping costs. (It cost me less to ship myself to Maquise and then *back* to Cayley, with the Savin, than to just ship the Savin?)
As for upgrading shops by spending money at them, I'm a bit leery of letting that get too expAnsive. Though I don't claim any levels in Shopkeeper, growing a given store indefinitely based on one person's custom seems dangerous to me. What when that customer leaves? A player-influenced faction should be more effective, either temporarily (joint Knights/Stars mech-show, as part of a Peace & Love playthrough?) or long-term (new factory).
Sidenote: What about "loyalty" based discounts? Each time you buy a certain quantity of items at once, you increase the merchant's attitude to you, the more they like you, the better their prices?
Hmm. I know there's a thing in GH1 where shopkeepers (typically mechanics) will comp me the occasional repair/reload fee because I've been a very good customer. (Yeah, town defense does tend to need a lot of mechanic work, at least to reload the Heavy Missiles on the Harpy.) Not sure how that works offhand, but probably not a bad place to start thinking about code-implementation.
If you're talking about just giving the currently-existing attitude/reaction score a kick upwards for buying, say, 20 Arc Thrusters in one go, not a bad idea--so long as shop selections get a bit more standardized, so we're actually talking about "loyalty" rather than"stocking up because it's never available". Would adding a time/proportionality* check, so that I get a discount if I routinely get mechanic services or rations from one particular shopkeeper, be useful?
Problem I just realized: shop locations, the spaceport mechanic for example. Rather easier to hit the loyalty threshold with the nearest store rather than going to someplace in the spinner. Might need to control for that.
*Examples: Time: Ka-lol has spent an average of $ credits/day or purchased an average of I Items/day over D days. Shopkeeper recognizes him and offers discount.
Proportionality: Ka-lol has spent 75% of the credits he spent in the entire spinner (once spinner-wide spending hits a certain amount) in this store. Shopkeeper recognizes him and offers discount.