Ultimately, what it boils down to is precisely what you said - I'd have to figure out a reason why J-1 ships would even be in the game. Part of the issues involved would be the initial start up costs of Jump 1 ships versus higher Jump ships. A Jump-1 200 ton Beowulf costs 28.9 Mcr to purchase and requires 5.78 down payment. A Jump-3 version of that 200 dton ship (ie all things such as staterooms, lowberths etc kept constant) costs 45.5 Mcr - and a 9.1 Mcr downpayment.
Beowulf-1: costs 28.9 Million, finances 28.9 Million for a monthly cost of 120,417 Credits per month. If it paid 9.1 Million up front, the amount financed would be 25.58 million with payments of 106,583 (a savings of 13,834 credits per month.
Beowulf-3: costs 9.1 Mcr down, and finances 45.5 million for a monthly payment of 189,583 Cr.
The real kicker is the delivery time requirements and such from Far Trader - it automatically excludes J-1 ships from participating in any shipments past 1 Parsec. By definition, a J-1 ship can't be "transient" traffic because it can only take 1 parsec cargo lots without incurring a late fee penalty of at least 27.1%
The ONLY way out of this that I can see, is to add two "house rules" to the mix. The first one is to make the delivery dates equal to 10 days per jump required plus 1 week. The second houserule is to apply a penalty to the captain's merchant skill equal to either the difference in "most efficient verus current drive" or twice the "most efficient verus current drive".
Example: Tom Swiftie wants to bid on cargo lots that need to be delivered to a world that is 3 parsecs away. The GM informs him that the most efficient traffic (read that as liner traffic) utilizes Jump 3. Efficiency of 3 minus Tom's jump 1 ship results in a -2 penalty to his merchant roll when securing bids on lots. Alternative rule as I mentioned (ie -2 per efficiency level) means that Tom Swiftie suffersr a -4 penalty to his merchant skill.
This way, Jump-1 ships can compete in a limited sense. They only get the tramp freighter market to begin with. They get penalized for less efficient ships without being priced entirely out of the market. Jump-1 ships tend to be transports of the last resort. Ironically? GURPS FARTRADER gives a +1 to +4 bonus to a captain's merchant roll for hazardous cargoes or fragile freight lots when it comes to bidding on them.
When it comes to Jump Mains, a 1 Parsec ship is the slowest travelling ship. It is more like a steam freighter in today's world. A Jump 2 ship is like a more modern freighter. A jump 3 ship is like a cargo transport airplane while a Jump 4 ship is like a Fast passenger type plane. There are still slow freighters chugging away on our ocean surfaces, but the numbers of such freighters are down from what it was in its heyday.
The only real "choice" I have as a GM in such a Traveller universe is to either outlaw Jump1 ships entirely as "nope, the shipyards won't build them any more" to "yup, they build them still" If they build them still, then the tramp freight market may require the GM to state flat out "This market is served by the left overs - the liners for what ever reason don't pick up the tramp freighter market as being unprofitable to them, or they just don't have the hull capacity to cover it. When I get done posting this - I'm going to set up an Excell spreadsheet cost analysis for various ships in GURPS TRAVELLER. Things like monthly payments, crew costs, etc. I'm almost tempted to believe that if a corporation can be set up to provide funds for capital investments, that such a corporation would not finance their ship, but pay for it entirely at once. Financing stock to the tune of 28.9 million and keeping the money saved by not paying for financing would amount to a yearly income of 1.445 Mcr per year (monthly financing costs x 12). This is a 5% return on investments per year. Hmmmmm.
I find it perhaps ironic, that the original Traveller economics rules made it impossible for Jump 2+ ships to survive economically - and the new GURPS FAR TRADER rules make it impossible for Jump 1 ships to survive economically.
