I would suggest some basic EDC items or basic utility thing that would be nice to have but you normally wouldn't spend money on.

Flashlights- https://www.amazon.com/dp/B078ZFJ3Z7/?coliid=I14KRBUUUCTDOC&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Hand warmer- https://www.amazon.com/dp/B013HLGTUS/?coliid=I2PPV1KPI66UH2&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Door stoppers if you travel.
https://www.amazon.com/dp/B06XVQN9W2/?coliid=IXHQN4C0UZIM6&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

Travel towels. https://www.amazon.com/dp/B07WMG6V5L/?coliid=I3TNYXNSJPCTCA&colid=85AQP6CWFMSS&psc=1&ref_=lv_ov_lig_dp_it

If you want to stick to cosplay and such maybe accessories for costumes or storage?

Heads for wigs. https://www.amazon.com/Wig-Mannequin-Head-Maniquins-Seamless/dp/B08T6DJ9XK/ref=mp_s_a_1_5?crid=314R2OGCB5BNA&keywords=maniquins+head+for+wig&qid=1636774427&sprefix=maniquins+head+f%2Caps%2C174&sr=8-5

Garment bags https://www.amazon.com/MARMINS-Dress-Gowns-Clear-Garment/dp/B08MYTXLZ6/ref=mp_s_a_1_1_sspa?crid=1KS13AIE3KMI1&keywords=travel+dress+garment+bag&qid=1636774548&sprefix=travel+dress+%2Caps%2C148&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFEUUNCNDhVR0NPOVomZW5jcnlwdGVkSWQ9QTA5NDI4OTMzQUFEUlNNRkQ4WURHJmVuY3J5cHRlZEFkSWQ9QTA2NTA2NDJZUktHOFU2S003Tkcmd2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==