The frames I use for each arch are a long term investment and I’ve built them up over time. Im lucky to own a large number which enables me to do multiple outdoor arches on the same day.
For me the key to owning this many frames is charging a fair price for 1 arch. The multiple hire of the first frame I purchased enabled the investment in a further 5 frames which quickly grew to 10 and now 20.
I still regularly replace and invest in new poles & pins but the main thing is the base plates. They are pretty much indestructable and having this many at hand allows me to double up (2 base plates screwed together) on really windy days.