$50 more for a smaller telescope.
From the add it did not become obvious whether or not the diagonal and/or any eyepieces would be included, so it appears as if the aditional costs are justified by the computerised mount only.
The usefulnes of such mount may be questioned though I have to admit to love my go-to mount. Here is a thought to the mount:
80mm aperture limits the ability to observe dim deep space objects (DSOīs) even more than 90 or 100mm, so what you are really in for are planets, moon, sun and the DSOīs that can be seen with the naked eye under good skies (they will resolve much better with the telescope). So what the mount does is either slewing automatically to database objects the user can already see or to database objects that the user will not be able to see with this telescope. Autotracking could be a valid point as it ensures that an object does not move out of the field of view (due to earths movement). But this is easily achieved manually (and without aditional costs for batteries). At least it offers a little amazement when the telescope starts moving by itself. The decision is yours.
Filters: a moon filter will be necessary to reduce the very bright glare and increase contrast. A sun filter will be necessary to safely observe this star. The baader sun filter foil works great and is very inexpensive:
http://www.astroshop.eu/filter-foils...-baader/p,2718. You would have to make a fitting filter for your telescope but this can be done with a bit carboard from a calender and some glue. The rest of the foil that you donīt need will sell well amongst others on the forum. The filter cuts out 99,99999% of the incoming light so it is safe to look directly in the sun. But be careful, if the filter falls off whilst the observation your eye will be irreparable damaged in less than a quarter of a second.
I think colour or special bandwidth filter would not be necessary given the small aperture.
Cheers