The short answer is yes, upgrading the SSD and RAM is much cheaper yourself.

I just put a second 1TB SSD in from Sony. It's considerably faster than the stock drive from Dell.
https://www.amazon.com/gp/product/B07MFZY2F2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

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Here's what I have next up for maxing out the machines RAM. Probably way more than needed for most people, but still relatively cheap considering.

https://www.amazon.com/dp/B07ZLCC6J8/?coliid=I2GU9M8B0Z6IW0&colid=3DZV7D2PZ9B5I&psc=1&ref_=lv_ov_lig_dp_it

I have this in my NUC7i5, works great.

For what it's worth for when you switch to 64gb, I have this kit in my nuc7i5bnh (Yeah I know you have a nuc8), and it works fine.

I just did a clean install 2wks ago... running 64GB ram

Crucial 64GB Kit (32GBx2) DDR4 2666 MT/S CL19 SODIMM 260-Pin Memory - CT2K32G4SFD8266

https://www.amazon.com/gp/product/B07ZLCC6J8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Added a faster NVMe Drive (3,500/3,200mb/s r/w)

SK hynix Gold P31 1TB PCIe NVMe Gen3 M.2 2280 Internal SSD - up to 3500MB/s

https://www.amazon.com/gp/product/B08DKB5LWY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

also threw an old 1TB Crucial MX500 into the 2.5 slot...

all worked great and booted right up