This is only a problem if the service provider is a monopoly (or if every service provider illegally coordinates price fixing).
I might be willing to pay up to $800 to fix a $1000 computer (a more expensive repair might cause me to look to buy a replacement rather than repairing). But if it’s a 1 hour job requiring $100 of parts, then all the computer repair shops would be competing with each other for my business, essentially setting their hourly rate for their labor. At that point it’s like bidding at auction up to a certain point, but expecting to still pay the lowest available price.
So the problem isn’t necessarily perfect pricing information from the other side, but lack of competition for pricing from the other side. We should be fighting to break up monopolies and punishing illegal price fixing.
Plenty of us Democrats are very much in support of a ranked choice voting schemes, or similar structural rules like non-partisan blanket primaries (aka jungle primaries). The most solidly Democratic state, California, has implemented top-2 primaries that give independents and third parties a solid shot for anyone who can get close to a plurality of votes as the top choice.
Alaska’s top four primary, with RCV deciding between those four on election day, is probably the best system we can realistically achieve in a relatively short amount of time.
Plenty of states have ballot initiatives that bypass elected officials, so people should be putting energy into those campaigns.
But by the time it comes down to a plurality-take-all election between a Republican who won the primary, a Democrat who won the primary, and various third party or independents who have no chance of winning, the responsible thing to make your views represented is to vote for the person who represents the best option among people who can win.
Partisan affiliation is open. If a person really wants to run on their own platform, they can go and try to win a primary for a major party, and change it from within.
TL;DR: I’ll fight for structural changes to make it easier for third parties and independents to win. But under the current rules, voting for a spoiler is throwing the election and owning the results.