What's the least expensive way to change the look of a 1984 motorhome?

The easiest way is to paint the inside in other colors, and use fabric for blinds, pillows and covers to cheer it up. Choosing light colors - shades of white, grey or beige - would help make it look lovely and clean. If you like bright colors, here's an example of house that has nothing dull in it, for your inspiration: http://gabiralea.ro/en/the-shabby-chic-house-everyone-would-love-to-own/. The easiest way to paint the interiors would be to choose three colors as an alternative - one instead of Burnt Orange, one for Brown, and the last one for Creamy White. If it would be mine, I would probably choose a shade of blue or turquoise to replace orange, grey instead of brown, and probably keep the white, but also add a pop of red or yellow. As for the fabrics, I would definitely go to Michaels, and probably choose stripes. I hope it helps. :)

we took off all the gold hardware and sprayed it silver. We let that dry and then spray a coat of polyurethane over them. We let them dry for two days before putting them back on. We also sprayed the screws to match. Hardware is expensiv. Spray paint and patience is not. We also trades out all the bulbs to the new LED bulbs. Really brightened up the place.

https://www.pinterest.com/odtravel/before-after-rv-renovations/?lp=true

Having been a Motor Home camping family when we had kids at home 30 years ago, I am very familiar with these colors! Most of them were dark and patterned to help hid dirt, mud, etc. brought in from the adventuring outside!

Spend the money and have everything reupholstered. Go with your taste, but keep in mind you do want something in the darker shades but with a splash of color. I am attaching a photo of a couple of chair colors I have. I do tend to like the dark woods on furniture!

You can make or buy lighter curtains. If they are too long, cut them off and use "stitch witchery" that is put between edges and ironed together for a hem.

Before I scrambled around trying to get this changed, I would take it to a dealer and see what a "change out" price would be. Upholstery is very expensive.

P.S. I forgot to attach photos..I am not recommending these patterns, just attaching them to show you prints can be bright!!

I've helped disabled clients of mine renovate RVs to make them cheery. Paint the wood cabinets lighter colors, I like the light uppers with the dark lower cabinets.

I've made new curtains with fabric from the thrift store, or get an old pair of curtains, a bedspread to cut up and make ... think my best set was a bay window I did with old lace tableclothes made into curtains.

If you have those pleated shades, I've soaked them clean in bleach and water in the tub, hang out side to dry out, try one of the small ones to make sure yours are washable. To insulate windows if your in a cold climate, make window inserts with bubble wrap or use the Reflextix mylar bubble insulation.

They make great peel n stick backsplashes that can also brighten up your kitchen. Amazon has some great ones.

Flooring, I like the luxury vinyl planking, the self-adhesive checkerboard vinyl squares, and the indoor outdoor carpeting. Shop sales, closeouts.

There are tons of videos on YouTube with folks renovating older RVs and travel trailers.... one of my favs... https://www.youtube.com/watch?v=Pm1oY38ybsQ when removing hardware put in bowls so nothings lost

https://www.youtube.com/watch?v=6yFvzzcbYxA

https://www.youtube.com/watch?v=O1Z2DH0wYl0