What is the best bang for the buck Bokeh lens for a D5300

[nerwin]

@DKtucson brings up another point. If you are willing to using full manual lenses, then have a look at Nikon's AIS lenses such as the 105 2.5 AIS, that produces some beautiful bokeh.

 

[DKtucson]

I have a 105/2.5 --old 1970's Nippon Kogoku (black & silver). Whoever owned it back in the day had the presence of mind to put an AIS mount on it. I still have my FE , an FG and a ton of manual lenses that all work (in manual mode) on my DSLR's.
As far as using M42 to AIS adapters--the cheapie ones with no correction glass for infinity focus can be had for about $1.50 from china on Ebay--ones with the glass are about $7-10 depending on the vendor. Here is a helios lens from a Zenit using a .99 cent adapter ring on a D100..I did not need infinity for this

 

[DKtucson]

With the cheapie non-infinity m42 adapter I get shallow DOF even shooting at smaller aperatures outdoors. For the record the Helios lens was $30 on Ebay from a russian vendor