So, you are ready to get your own instrument. Here are some things to help you on your first purchase. We will look at these factors: size, quality, cost, and suppliers.
We picked the Kohala loaner ukes for a reason: These entry-level concert instruments are a good balance in terms of low-cost, portability, sound volume and traditional ukulele resonant tone. If in doubt, stay with the concert size.
Bottom line on the 4 basic sizes: 1) Soprano is easiest to hold, most traditional uke sound, not the easiest to play. 2) Concert has the best mix of traits for general playing. 3) Tenor has a little more volume and mellower sound, good with low-g tuning. 4) Baritone has lower note range, more volume, but different tuning. Here is a good video on ukulele size comparisons. worth your time.
3 ranges in quality: 1) Entry-level instruments are the cheapest models that will produce an acceptable sound. They use laminated materials and cheaper tuners. Brands include Ashthorpe, Kohala & Luna.
2) Mid-range ukes employ better woods like spruce and mahogany, mostly laminated, with better fit-and-finish. Kala and Lanikai are 2 examples here, but they produce all ranges of instruments.
3) High-end ukes are prettier and more resonant. Solid wood construction with more exotic types. The most prized varieties are Hawaiian mahogany and koa. It is probably too soon for you to jump into this pool. I can't say that a $500 uke sounds 4 times better than one for $125.
Cost: Prices have risen a lot since the pandemic so be prepared to apply an inflation factor. But in general, expect to pay 50-90 for a new entry level model with basic accessories; 100-250 for mid range; $400 and up on the high end.
Suppliers: There are a few local retailers of interest. I do not recommend Guitar Center due to a weak inventory of both instruments and accessories. Menchey Music on Mannheim Pike is a better bet. That is where your loaners came from. But the best option is Funky Frets in Boyertown, which specializes in ukes of all sorts. The owner is a player & teacher and a good guy. A long trip, but worth it to try out a lot of instruments.
Online sources abound. For entry-level models, the big retailers, like Amazon and Walmart, do well. A better bet for upscale models are the music retailers-- Sweetwater Music and Elderly Instruments. They both have good customer service and set up the instruments well before shipping them out.
You would think that there would be a big market for used instruments, but I have not found much in that regard. Elderly sells used instruments, but they tend to be vintage models. There is a large guitar swap meet locally; maybe some ukes will show up there in future.
Good luck, and aloha!