John3M
...what I have discovered is the inexpensive and sometimes cheap older models have poor instructions and the fit well not so good....
That's as true today as it is for kits made in the 50s, 60s, 70s. You can make an argument that quality is generally higher today than it was years ago. But it really depends on the brand and the kit.
If you're looking for more reasonably-priced kits from the 50s, 60s, 70s, with good instructions, I would look at Monogram, for 1/48 aircraft, for their 1/35 and 1/32 armor kits, and for their 1/24 and 1/25 scale cars. I would look at Revell, for their 1/24 and 1/25 scale car kits, for their 1/32 and 1/72 scale airplanes, for their WWII warships in various scales (they designed their kits originally to fit standard boxes, not to constant scale) and in 1/720 scale. Airfix had a broad catalog, including 1/72 aircraft, 1/72 scale and HO scale armor, as well as ships in various scales, figures both solid and to assemble, and larger-scale aircraft.
Those makers all placed great worth on the quality of their kits, including the quality of their instructions. Monogram, for example, would produce a prototype of a kit and instructions, then invite Boy Scout troops to come in and build. That provided a quality control step to the process. And they included details about the parts. You could learn a lot about the subject from reading the instructions.
Sadly, companies moved away, generally, from detailed instructions to documents that were basically exploded drawings with little or no explanation of what the parts were.
We've come full circle in some regards, in that some manufacturers do put as much effort into their instructions as into the engineering of their kits. They produce instruction documents that are more like a Squadron "In Action" booklet. I think of Eduard, Dorawings, Wingnut Wings, just off the top of my head.
As far as old Monogram and Revell kits go, many of their subjects are still available in more recent boxings. But I prefer to buy the old, pre-merger issues. It helps to educate yourself, but a good rule of thumb is to look for the old "white box" releases from the 70s. You can generally find them cheap on the secondary market, especially if you look for boxes that were opened, which collectors will pass up. I still buy and build the Monogram airplanes from the 60s and 70s-the P-51B, P-40B, the Spitfire, the Typhoon, the Hellcat, Wildcat, Avenger, Dauntless, the P-39, the large multi-engined aircraft. You can find them for reasonable prices, they can be built into decent representations of the subject, you can hone your skills on them, and have fun.
As far as contemporary kits go, I like Eduard's 1/48 scale aircraft, and that they will release a kit in various levels of price, depending on the additional items included, from weekend editions to the higher-end boxings with more PE, decals, etc, etc.
And Airfix has been revisiting its catalog and issuing new tooling of subjects it did previously. The engineering and detailing are improved, taking account of today's modeler's expectations, but without making the kits prohibitively expensive. I really like the P-40B they released several years ago, for its quality and a price that wasn't too bad.
Others will have tips and their own preferences to share, too, I'm sure.