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The 10mm's eye-relief is already a bit short but tollerable. IMHO Get the 6mm gold-line for planets ($19-$25). More magnification, longer eye-relief. 66° apparent field of view.
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Just use the supplied 26mm as overview eyepiece for now. Look around for a used 30-38mm 70° eyepiece.
If the 26mm is a Plössl as well, the difference in field of view is not overly large (1.12° vs 1.4°).
IF the included eyepiece is the 2" 26mm q70, you already have a decent overview eyepiece. 30mm can work as well, but the 26mm's exit pupil is better suited for some light pollution.
If you get the cheap 15mm and 6mm, you only need to spend
That would even leave some budget if the telescope includes a simpler 26mm eyepiece. If it includes the 2" 26mm eyepiece, you could spend the rest on something like a 9mm 66°, collimation tools, filters, books. :-)