I am now using the technology of Patreon to enable me to offer patrons a way of accruing buying power (for art) over time in small increments. It's like a payment plan in reverse, where automatic deposits are made on a monthly basis with funds that you wish to allocate towards the purchase of artwork. Whenever you decide on a work, you then simply use those funds to make the purchase. I find that this is structured in a way helpful to both the artist (myself) and the patron. On the artist side, it allows for artists to stablize a degree of monthly income (since usual art purchasing practices can be wildly unpredictable) which thereby enables the artist to better budget for expense/spending throughout the year. For patrons, it helps to spread out payments so that the purchase of an artwork can be done over time.
You can find out more information by visiting my patron page, where you can also choose to formally become my patron, should you feel inspired to do so.