I saw it too : there's a 4" version that I would rather have.
http://www.optcorp.com/product.aspx?...0-605-873-9181
Think it woulld be cheaper to buy a big fast zoom telephoto.
I was looking at going for a nice fast Fluorite APO or ED APO in 100-110mm range last year but decided against it and to sit on the money.
The field flattener / telecompressor lenses are murder pricewize.
This was to replace my stolen Vixen Fluorite 4" APO and GP-DX mount , which was lifted when some toe-rag broke into my garage. Roller door locks are not very secure. Good thing I had contents insurance on my home.
And some have optical elements very close to focusor end of the telescope too. I think the Taks do this.