I've always favoured parallax maps, simply because they do look better and you can do more with them, without having to make individual tiles to recreate the effect. But they do take considerable time to make.
To avoid getting bored, consider creating maps which use the default mapping to begin with. This lets you get on with the important bits like developing the story and expanding the game. That helps you to keep progress going. Somtimes, though you might get to a point where you want to just take a break from the story stuff too, at which point you can go back over some of the maps and make some decisions about the way the look.
Not all maps need to parallaxed, even in part. They might completely serve their purpose and adding in random complex "tiles" probably isn't necessary. But you might see a few places where a bit of a touch up with parallax seems like a good idea. You can identify areas that players will come across more often and more readily, and those should be the main focus for graphical touch up.
Seeing as you don't have a single person dedicated to graphics and maps, you do need work out where your time should be invested for the most returns. Good graphics these days will always help to set the game apart visually from the generic RM games we have. But for the most part, people expect to see average graphics and are more interested in the actual game itself.
Not only that, but you can always update the graphics on the game even after a release of the final thing, assuming that you were willing to put in the time then. If you get good reviews from people, it might encourage you try to do some more for them. Similarly, you can even add in special areas that are included to get people to play the game again/update their current game.
If there's anything I can do to help, you only have to ask. I'm not sure what I can do, and I don't want to be doing a huge amount either (working on my own things too, y'know
). But a little bit here and there to help out, I can do that.