A cheap option is buy an esp32 board (with a case) and flash the firmware of Blockstream Jade (bitcoin only). This is a technical and experimental DIY, but if you not willing to spend for an original Jade, this might be the option

How to: https://youtu.be/PeqP6oVnlIs?si=78GONB_yiukVrCO7

Hardware: https://www.aliexpress.com/item/33048962331.html?browser_id=b1e68eb20db74f9ea1306161559e3c16&aff_trace_key=fbdb2763c23b4760b9c4a4903159fddd-1692199879194-06211-_DduLyh3&aff_platform=msite&m_page_id=ntphddmcabuqlgka18a42af49001da1e6b521f802c&gclid=&pdp_npi=4%40dis%21EUR%2121.79%2117.06%21%21%2123.06%21%21%40211bd8be16933358983714290d077b%2112000031555127810%21sea%21DE%210%21A&algo_pvid=85f48247-6667-4b5b-b3c8-a496ff0f3ab5