Looking to get the Appareo esg adsb out or the Garmin 335 for $3,000 installed in my RV6. I saw an ad for the Appareo installed @$4,300 and 3 days down, some discount the unit by $300, is the install that long and $1,600, any rebate to the shop from Appareo to sell the unit, Garmin box any cheaper to install?