HK$150 = making money?
Well thats the market price for PROFESSIONAL VHS to DVD conversion -pls check around the web .i.e US$25-35 per 30 mins.[not even per tape]
The 'AV to PC' method you suggest is very low tech and result will be very poor resolution and 'lossy'.
These historical Avaition videos deserved to be converted using professional quality equipment and archived for prosperity.
Professional method: Professional Grade VCR-Video capture device-PC-DVD Burner or 'lossless'.