After 25 years or so with a pair of 35mm Canon SLR cameras, I took a 'nibble' of the digital age about 2002 with a Canon G3. That evolved to a G5 2-3 years later, but I knew one day I'd bite the bullet on a DSLR. I started with a used 30D and EF-S 18-135 lens. From then on, it was one piece at a time as my photo skills improved.
Unlike Johnny Cash that built his car one piece at a time
https://www.youtube.com/watch?v=ws-_syszg84
and ended up with a wild conglomeration, I slowly figured out what I needed that the 30D + 18-135 couldn't supply. First was more lighting. So I bought the high end Canon flash at the time, a 550EX. I figured I could always dial back the flash, but couldn't dial up the flash if it was too small to start with. To get better ISO speeds and more pixels to handle significant cropping I'd sometimes did (rethinking the framing, cutting out extraneous stuff), I upgraded to a 60D.
As I evolved to mostly indoor church events other than weddings and realized that low light no flash shooting (to avoid startling anyone at important times), I knew I needed faster glass (f2.8, etc). So, I replaced my two EF-S lenses (I had bought a 55-250 along the way) with faster Canon EF lenses that covered 99 percent of the focal ranges I normal shot at. I had a couple of mis-steps and bought and later sold 2 primes and a zoom along the way before I finally settled into my 'fantastic four' - 3 fixed aperture zooms and the EF 135 f2L. I was still struggling to keep fast enough shutter speeds to stop subject motion, get sufficient DOF, and minimal easy to clean up in post noise levels. The 5D mark iii hit the streets about the same time and between its high ISO capabilities and super accurate focusing, I knew I had to have it. After saving up a while and denting my credit card a bit, I made the leap.
Like most amateur photographers or any other hobbiests with expensive hobbies, my financial limits restricted how fast I was upgrading and adding to my camera bag. I quickly realized I had to sell the lenses I just didn't 'work' for me to pay for something else...and throw in more $$$. Part of the reason for selling off the lenses was because of a case of GAS (gear acquisition syndrome). Fortunately, from lenses to flash brackets and a couple of other doo-dads I didn't need, I was able to recoup a good percentage of the cost of those items when I sold them.
In short, a slow pace and figuring out what I needed to get the results I wanted is the best path, in my estimation. The slow pace allowed me to keep up with my bills and not get too far in the hole with my credit cards.